Just to throw in my own (non-tech) idea, which originally led me to wonder what other people's capital-intensive ideas might be:

I would open up bookstores with a Netflix-like business model. You pay something like $5/month to use it, read any books you want without buying them and not feeling like a freeloader. There can be monthly family plans etc., and when someone does buy a book, their fee for that month can be waived.

Clearly, despite having an entire bookstore in their pockets, people want a physical place to socialize and read, and this offers them a way to do that in the 21st century.